1. Field of the Invention
The present invention relates to heat exchangers and, more particularly, to a heat exchange module for use in an improved heat exchanger assembly.
2. Prior Art
Various different types of heat exchangers are known in the art. U.S. Pat. No. 4,470,454 to Laughlin et al discloses a plate type annular heat exchanger. U.S. Pat. No. 4,431,050 shows a similar heat exchanger adapted for use as a regenerator for a gas turbine engine. U.S. Pat. No. 4,582,126 discloses an annular heat exchanger assembly having a plurality of members U.S. Pat. No. 3,289,757 to Ruthledge discloses a polygonal heat exchanger.
Various problems have arisen with annular heat exchangers. The principal problem is that the radial flow of hot gases in an annular heat exchanger from an inner aperture or circumference to an outer circumference results in unequal temperatures in a thermally inflexible system. Typically, with radial outflow of hot gases, this results in a relatively hot section near the inner aperture and a relatively cool section near the outer circumference. In the prior art plate-type heat exchangers, this leads to high plate stresses, especially when the inlet temperatures are not uniform, thus reducing the working life of the heat exchanger.
Another problem is that the total heat transfer area in radial outflow annular heat exchangers is limited due to the need to collect the exhaust gas for discharge through a single outlet within a minimum system volume.
A further problem with annular heat exchangers of the prior art is that they are not easy to manufacture, repair, or replace.
It is therefore an objective of the present invention to provide an annular heat exchanger having rectilinear heat exchange fluid flow paths with improved heat transfer between fluids.
It is another objective of the present invention to provide an annular heat exchange assembly which achieves thermal flexibility by construction of a heat exchange module that can be used with similar modules to form an annular heat exchanger with a rectilinear heat transfer means.
It is another objective of the present invention to provide a heat exchange module that can be used with similar heat exchange modules to form different polygonal shaped heat exchangers which can provide maximum heat transfer for a specified volume in which the heat exchanger must operate.
It is another objective of the present invention to provide a heat exchange module for use in an annular heat exchanger that can be easily replaced.